부산대학교 도서관

Abstract: Constraint loss adjustments, based on finite element (FE) stress analysis and local critical stress, σ *, critical stressed volume, V *, cleavage criteria were applied to fracture toughness data from small pre-cracked bend bars of the IEA heat of F82H irradiated to 6.6dpa at 300°C in the High Flux Isotope Reactor. The 100MPa√m master curve method reference temperature shifts were evaluated based on both the measured toughness (ΔTm ) and after size-adjusting the toughness to small-scale yielding conditions at reference specimen size (ΔTo ) with values of ≈142 and 205°C, respectively. The model based prediction ΔTo = Co Δ〈σ fl〉, where Co ≈0.68 and Δ〈σ fl〉 is the change in the average flow stress over 0–10% strain is in excellent agreement with ΔTo . The FE analyses also demonstrates an upper-bound K Jc that can be measured with these small bend bars for irradiated alloys that suffer severe loss of strain hardening. [Copyright &y& Elsevier]